﻿using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace Scharfrichter.Codec
{
    static public class Util
    {
        public static long[] Primes = new long[]
        {
            2,     3,     5,     7,     11,    13,    17,    19,    23,    29, 
            31,    37,    41,    43,    47,    53,    59,    61,    67,    71, 
            73,    79,    83,    89,    97,    101,   103,   107,   109,   113, 
            127,   131,   137,   139,   149,   151,   157,   163,   167,   173, 
            179,   181,   191,   193,   197,   199,   211,   223,   227,   229, 
            233,   239,   241,   251,   257,   263,   269,   271,   277,   281, 
            283,   293,   307,   311,   313,   317,   331,   337,   347,   349, 
            353,   359,   367,   373,   379,   383,   389,   397,   401,   409, 
            419,   421,   431,   433,   439,   443,   449,   457,   461,   463, 
            467,   479,   487,   491,   499,   503,   509,   521,   523,   541, 
            547,   557,   563,   569,   571,   577,   587,   593,   599,   601, 
            607,   613,   617,   619,   631,   641,   643,   647,   653,   659, 
            661,   673,   677,   683,   691,   701,   709,   719,   727,   733, 
            739,   743,   751,   757,   761,   769,   773,   787,   797,   809, 
            811,   821,   823,   827,   829,   839,   853,   857,   859,   863, 
            877,   881,   883,   887,   907,   911,   919,   929,   937,   941, 
            947,   953,   967,   971,   977,   983,   991,   997,   1009,  1013, 
            1019,  1021,  1031,  1033,  1039,  1049,  1051,  1061,  1063,  1069, 
            1087,  1091,  1093,  1097,  1103,  1109,  1117,  1123,  1129,  1151, 
            1153,  1163,  1171,  1181,  1187,  1193,  1201,  1213,  1217,  1223, 
            1229,  1231,  1237,  1249,  1259,  1277,  1279,  1283,  1289,  1291, 
            1297,  1301,  1303,  1307,  1319,  1321,  1327,  1361,  1367,  1373, 
            1381,  1399,  1409,  1423,  1427,  1429,  1433,  1439,  1447,  1451, 
            1453,  1459,  1471,  1481,  1483,  1487,  1489,  1493,  1499,  1511, 
            1523,  1531,  1543,  1549,  1553,  1559,  1567,  1571,  1579,  1583, 
            1597,  1601,  1607,  1609,  1613,  1619,  1621,  1627,  1637,  1657, 
            1663,  1667,  1669,  1693,  1697,  1699,  1709,  1721,  1723,  1733, 
            1741,  1747,  1753,  1759,  1777,  1783,  1787,  1789,  1801,  1811, 
            1823,  1831,  1847,  1861,  1867,  1871,  1873,  1877,  1879,  1889, 
            1901,  1907,  1913,  1931,  1933,  1949,  1951,  1973,  1979,  1987, 
            1993,  1997,  1999,  2003,  2011,  2017,  2027,  2029,  2039,  2053, 
            2063,  2069,  2081,  2083,  2087,  2089,  2099,  2111,  2113,  2129, 
            2131,  2137,  2141,  2143,  2153,  2161,  2179,  2203,  2207,  2213, 
            2221,  2237,  2239,  2243,  2251,  2267,  2269,  2273,  2281,  2287, 
            2293,  2297,  2309,  2311,  2333,  2339,  2341,  2347,  2351,  2357, 
            2371,  2377,  2381,  2383,  2389,  2393,  2399,  2411,  2417,  2423, 
            2437,  2441,  2447,  2459,  2467,  2473,  2477,  2503,  2521,  2531, 
            2539,  2543,  2549,  2551,  2557,  2579,  2591,  2593,  2609,  2617, 
            2621,  2633,  2647,  2657,  2659,  2663,  2671,  2677,  2683,  2687, 
            2689,  2693,  2699,  2707,  2711,  2713,  2719,  2729,  2731,  2741, 
            2749,  2753,  2767,  2777,  2789,  2791,  2797,  2801,  2803,  2819, 
            2833,  2837,  2843,  2851,  2857,  2861,  2879,  2887,  2897,  2903, 
            2909,  2917,  2927,  2939,  2953,  2957,  2963,  2969,  2971,  2999, 
            3001,  3011,  3019,  3023,  3037,  3041,  3049,  3061,  3067,  3079, 
            3083,  3089,  3109,  3119,  3121,  3137,  3163,  3167,  3169,  3181, 
            3187,  3191,  3203,  3209,  3217,  3221,  3229,  3251,  3253,  3257, 
            3259,  3271,  3299,  3301,  3307,  3313,  3319,  3323,  3329,  3331, 
            3343,  3347,  3359,  3361,  3371,  3373,  3389,  3391,  3407,  3413, 
            3433,  3449,  3457,  3461,  3463,  3467,  3469,  3491,  3499,  3511, 
            3517,  3527,  3529,  3533,  3539,  3541,  3547,  3557,  3559,  3571, 
            3581,  3583,  3593,  3607,  3613,  3617,  3623,  3631,  3637,  3643, 
            3659,  3671,  3673,  3677,  3691,  3697,  3701,  3709,  3719,  3727, 
            3733,  3739,  3761,  3767,  3769,  3779,  3793,  3797,  3803,  3821, 
            3823,  3833,  3847,  3851,  3853,  3863,  3877,  3881,  3889,  3907, 
            3911,  3917,  3919,  3923,  3929,  3931,  3943,  3947,  3967,  3989, 
            4001,  4003,  4007,  4013,  4019,  4021,  4027,  4049,  4051,  4057, 
            4073,  4079,  4091,  4093,  4099,  4111,  4127,  4129,  4133,  4139, 
            4153,  4157,  4159,  4177,  4201,  4211,  4217,  4219,  4229,  4231, 
            4241,  4243,  4253,  4259,  4261,  4271,  4273,  4283,  4289,  4297, 
            4327,  4337,  4339,  4349,  4357,  4363,  4373,  4391,  4397,  4409, 
            4421,  4423,  4441,  4447,  4451,  4457,  4463,  4481,  4483,  4493, 
            4507,  4513,  4517,  4519,  4523,  4547,  4549,  4561,  4567,  4583, 
            4591,  4597,  4603,  4621,  4637,  4639,  4643,  4649,  4651,  4657, 
            4663,  4673,  4679,  4691,  4703,  4721,  4723,  4729,  4733,  4751, 
            4759,  4783,  4787,  4789,  4793,  4799,  4801,  4813,  4817,  4831, 
            4861,  4871,  4877,  4889,  4903,  4909,  4919,  4931,  4933,  4937, 
            4943,  4951,  4957,  4967,  4969,  4973,  4987,  4993,  4999,  5003, 
            5009,  5011,  5021,  5023,  5039,  5051,  5059,  5077,  5081,  5087, 
            5099,  5101,  5107,  5113,  5119,  5147,  5153,  5167,  5171,  5179, 
            5189,  5197,  5209,  5227,  5231,  5233,  5237,  5261,  5273,  5279, 
            5281,  5297,  5303,  5309,  5323,  5333,  5347,  5351,  5381,  5387, 
            5393,  5399,  5407,  5413,  5417,  5419,  5431,  5437,  5441,  5443, 
            5449,  5471,  5477,  5479,  5483,  5501,  5503,  5507,  5519,  5521, 
            5527,  5531,  5557,  5563,  5569,  5573,  5581,  5591,  5623,  5639, 
            5641,  5647,  5651,  5653,  5657,  5659,  5669,  5683,  5689,  5693, 
            5701,  5711,  5717,  5737,  5741,  5743,  5749,  5779,  5783,  5791, 
            5801,  5807,  5813,  5821,  5827,  5839,  5843,  5849,  5851,  5857, 
            5861,  5867,  5869,  5879,  5881,  5897,  5903,  5923,  5927,  5939, 
            5953,  5981,  5987,  6007,  6011,  6029,  6037,  6043,  6047,  6053, 
            6067,  6073,  6079,  6089,  6091,  6101,  6113,  6121,  6131,  6133,
            6143,  6151,  6163,  6173,  6197,  6199,  6203,  6211,  6217,  6221,
            6229,  6247,  6257,  6263,  6269,  6271,  6277,  6287,  6299,  6301, 
            6311,  6317,  6323,  6329,  6337,  6343,  6353,  6359,  6361,  6367, 
            6373,  6379,  6389,  6397,  6421,  6427,  6449,  6451,  6469,  6473, 
            6481,  6491,  6521,  6529,  6547,  6551,  6553,  6563,  6569,  6571, 
            6577,  6581,  6599,  6607,  6619,  6637,  6653,  6659,  6661,  6673, 
            6679,  6689,  6691,  6701,  6703,  6709,  6719,  6733,  6737,  6761, 
            6763,  6779,  6781,  6791,  6793,  6803,  6823,  6827,  6829,  6833, 
            6841,  6857,  6863,  6869,  6871,  6883,  6899,  6907,  6911,  6917, 
            6947,  6949,  6959,  6961,  6967,  6971,  6977,  6983,  6991,  6997, 
            7001,  7013,  7019,  7027,  7039,  7043,  7057,  7069,  7079,  7103, 
            7109,  7121,  7127,  7129,  7151,  7159,  7177,  7187,  7193,  7207,
            7211,  7213,  7219,  7229,  7237,  7243,  7247,  7253,  7283,  7297,
            7307,  7309,  7321,  7331,  7333,  7349,  7351,  7369,  7393,  7411,
            7417,  7433,  7451,  7457,  7459,  7477,  7481,  7487,  7489,  7499,
            7507,  7517,  7523,  7529,  7537,  7541,  7547,  7549,  7559,  7561,
            7573,  7577,  7583,  7589,  7591,  7603,  7607,  7621,  7639,  7643,
            7649,  7669,  7673,  7681,  7687,  7691,  7699,  7703,  7717,  7723,
            7727,  7741,  7753,  7757,  7759,  7789,  7793,  7817,  7823,  7829,
            7841,  7853,  7867,  7873,  7877,  7879,  7883,  7901,  7907,  7919 
        };
        public static int PrimeCount = Primes.Length;

        public static string alphabetBME = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        public static string alphabetDec = "0123456789";
        public static string alphabetHex = "0123456789ABCDEF";

        public static byte[] ByteSwap(byte[] target, int width)
        {
            int count = target.Length;
            int remainder = count;
            byte[] result = new byte[count];

            for (int i = 0; i < count;)
            {
                byte[] prev = new byte[width];
                Array.Copy(target, i, prev, 0, Math.Min(width, remainder));
                remainder -= width;
                for (int j = width - 1; j >= 0; j--)
                {
                    result[i] = prev[j];
                    i++;
                }
            }
            return result;
        }

        public static void ByteSwapInPlace16(byte[] target)
        {
            int count = (target.Length >> 1) << 1;
            byte temp = 0;
            for (int i = 0; i < count; i += 2)
            {
                temp = target[i];
                target[i] = target[i + 1];
                target[i + 1] = temp;
            }
        }

        public static Fraction CalculateMeasureRate(Fraction bpm)
        {
            Fraction result = new Fraction();
            result.Numerator = 240 * bpm.Denominator;
            result.Denominator = bpm.Numerator;
            return Fraction.Reduce(result);
        }

        private static int ConvertFromAlphabetString(string value, string alphabet)
        {
            int result = 0;
            int alphabetLength = alphabet.Length;

            while (value.Length > 0)
            {
                result *= alphabetLength;
                int index = alphabet.IndexOf(value.Substring(0, 1));
                if (index > 0)
                    result += index;
                value = value.Substring(1);
            }

            return result;
        }

        private static string ConvertToAlphabetString(int value, int places, string alphabet)
        {
            string result = "";
            int alphabetLength = alphabet.Length;
            while (places > 0)
            {
                result = alphabet.Substring(value % alphabetLength, 1) + result;
                value /= alphabetLength;
                places--;
            }

            return result;
        }

        public static string ConvertToBMEString(int value, int places)
        {
            return ConvertToAlphabetString(value, places, alphabetBME);
        }

        public static string ConvertToDecimalString(int value, int places)
        {
            return ConvertToAlphabetString(value, places, alphabetDec);
        }

        public static string ConvertToHexString(int value, int places)
        {
            return ConvertToAlphabetString(value, places, alphabetHex);
        }

        public static int GetLineReductionDivisor(int[] offsets)
        {
            int offsetCount = offsets.Length;
            int result = 1;
            bool finished = false;

            if (offsets.Length == 0)
                return result;

            for (int i = 0; i < PrimeCount; i++)
            {
                bool success = true;
                bool nonzero = false;
                int prime = (int)Primes[i];
                int divisor = result * prime;
                while (success)
                {
                    for (int j = 0; j < offsetCount; j++)
                    {
                        int value = offsets[j];
                        if (value != 0)
                        {
                            nonzero = true;
                            if (prime > value)
                            {
                                finished = true;
                                success = false;
                                break;
                            }
                            if (value % divisor != 0)
                            {
                                success = false;
                                break;
                            }
                        }
                    }
                    if (finished || (!nonzero))
                        break;
                    if (success)
                    {
                        result *= prime;
                        divisor *= prime;
                    }
                }
                if (finished || (!nonzero))
                    break;
            }

            return result;
        }

        public static string TrimNulls(string value)
        {
            if (value.Contains((char)0))
                value = value.Substring(0, value.IndexOf((char)0));
            return value;
        }
    }
}
